1. Field of the Invention
The present invention is generally related to systems and methods for a building lighting system that is powered using Power over Ethernet.
2. Related Art
Presently, many buildings have complicated electrical wiring systems that are installed when the building is first built. These wiring systems are typically required to be installed by a certified electrician, and the placement of overhead lighting and electrical outlets is predetermined by the wiring system that is pre-installed in the building. After the building is built, adding or moving light fixtures may be complicated and costly, requiring substantial re-wiring by an electrician.
Each light in a building may also be connected to a light switch module that is used for turning it on and off. The placement of this switch is also pre-determined by the electrical wiring system when the building is first built. Moving the placement of the light switch modules, or altering the control of the switch later typically also requires an electrician to re-wire the relevant portion of the house, which can be very complicated and costly.
These existing electrical distribution systems are typically high voltage (100-250V) AC (alternating current). Newer lighting technologies, like LED (light-emitting diode) lights, are more efficient than incandescent and even fluorescent lighting. However, they are inherently low voltage DC (direct current) driven devices. Adapting these devices to work in an existing AC distribution system requires conversion of the power sources, resulting in additional costs and complications.
Furthermore, existing light dimming schemes developed for AC powered incandescent bulbs do not work well by simply replacing the incandescent bulb with an LED light. Common dimming problems associated with using existing light dimming schemes with LED lights include flickering and flashing of the LED lights at low lighting levels, and an inability to dim below 10% of maximum lighting level.
Power over Ethernet, or PoE, is a standardized system to pass direct current (DC) electrical power along with data on Ethernet cabling. It allows a single cable to provide both a data connection and electrical power. It has typically been used to power devices requiring a small amount of energy, such as a phone or small camera. Unlike other standards such as universal serial bus (USB) which also power devices over data cables, PoE allows long cable lengths. However, PoE systems have not been previously used to power traditional lighting systems in a building.